import math

class MyMath:
    def perimeter(r):#圆的周长
        return math.pi * 2 * r
    def area(r):#圆的面积
        return math.pi * r * r
    def s_area(r):#球的表面积
        return math.pi * 4 * r * r
    def volume(r):#球的体积
        return math.pi * (4/3) * r * r * r

if __name__ == '__main__':
    r = float(input("请输入半径："))
    print("圆的周长={0:.2f}".format(MyMath.perimeter(r)))
    print("圆的面积={0:.2f}".format(MyMath.area(r)))
    print("球的表面积={0:.2f}".format(MyMath.s_area(r)))
    print("球体体积={0:.2f}".format(MyMath.volume(r)))

